ABCL-BUILD now more usefully installs necessary build machinery.
Refactor the ABCL-BUILD Lisp based build to use use Ant, which allows
us to canonicalize the build instructions in a much more configurable
manner, restoring the cross-implementation build of ABCL for CL users
who really do want to know about Java tooling.
Since we want to use ASDF/UIOP anyways, this code is best expressed as
an abcl contrib where such behavior can profitably take place.
TODO: does not pass all tests
TODO: API compatibility so that build-from-lisp.bash works
TODO: If an invocable Ant cannot be found, then offer to install one via restart
TODO: work backwards to the scenario that we are booting in pure
interepreted mode without access to compilers.